A 6-year-old boy was referred to us after an abnormal shadow was detected in the left upper lung field on a chest X-ray taken as part of a school cardiac screening program. We suspected an intrathoracic lipoblastoma on the basis of blood test results and CT, MRI, and other imaging findings, and we performed a surgical resection for diagnostic and therapeutic purposes. The pathological diagnosis was also lipoblastoma, and two years have passed without any postoperative complications. Lipoblastoma is a relatively rare benign tumor that is most commonly found on the trunk and extremities of infants, but cases like this one of a lipoblastoma in the thoracic cavity are extremely rare.
